Don't get me wrong: I love hacking on compilers and I do it for fun. And you can ship a production compiler in a year. But for C++ 11? That's a different beast. That's a language that's neither fun to write a compiler for nor do I think it's tractable to write one in a year (but who knows?)
The company was Sycor--unlikely anyone has heard of it. They invented the Intelligent Terminal--a data entry device replacing keypunches that could do validation checks on entered data.
They were building an 8085 powered computer with their own OS. They hacked the PL/M compiler--actually rewrote it in Fortran to emit the appropriate object code and the rest of their tool chain. They started an effort to rewrite the compiler, but it failed. I came in, and being familiar with XPL (From the book "A Complier Generator"), having finished a port of it for the Xerox Sigma 5 at a previous gig. One other person on the team had finished a PhD in computational complexity and the other had project experience writing COBOL compilers.
The project stared with a desire to change the language a bit, so we designed a new language. It wasn't too different from PL/M as it had to be mechanically translatable. The language was named, embarrassingly, Syclops. We started out with batch jobs on a 360/35, writing it in PL/1. They shortly got a PDP-10, which I miss, and we commenced to rewrite the compiler in Bliss-36. So it was essentially a cross-compiler, spitting out 8085 machine code with a very fancy assembler listing, including timings for each basic block.
The project was wildly successful, and opened the door to switching processers. For a while, they considered the 6809, but ultimately stuck with the 8085. The CEO was very pleased, at least, to have the opportunity to consider the switch.
My favorite activity was taking bug reports from the programmers who always looked at the generated code. The would come in with the listing, saying that the code was wrong. I would go over the code, and the reaction from them always was "wait--that is odd, the code is right. Weird."
My boss at the time like to say "A compiler should produce code that an assembly-language programmer would be fired for writing."
Out of curiosity, what was the compiler for?